/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package org.apache.jmeter.control;

import java.io.Serializable;

import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.property.BooleanProperty;
import org.apache.jmeter.testelement.property.IntegerProperty;
import org.apache.jmeter.testelement.property.JMeterProperty;
import org.apache.jmeter.testelement.property.StringProperty;

/**
 * Class that implements the Loop Controller.
 */
public class LoopController extends GenericController implements Serializable {

	private final static String LOOPS = "LoopController.loops"; // $NON-NLS-1$
	
	private static final long serialVersionUID = 232L;

	/*
	 * In spite of the name, this is actually used to determine if the loop controller is repeatable.
	 * 
	 * The value is only used in nextIsNull() when the loop end condition has been detected:
	 * If forever==true, then it calls resetLoopCount(), otherwise it calls setDone(true).
	 * 
	 * Loop Controllers always set forever=true, so that they will be executed next time
	 * the parent invokes them.
	 * 
	 * Thread Group sets the value false, so nextIsNull() sets done, and the Thread Group will not be repeated.
	 * However, it's not clear that a Thread Group could ever be repeated.  
	 */
	private final static String CONTINUE_FOREVER = "LoopController.continue_forever"; // $NON-NLS-1$

	private transient int loopCount = 0;

	public LoopController() {
		setContinueForever_private(true);
	}

	public void setLoops(int loops) {
		setProperty(new IntegerProperty(LOOPS, loops));
	}

	public void setLoops(String loopValue) {
		setProperty(new StringProperty(LOOPS, loopValue));
	}

	public int getLoops() {
		try {
			JMeterProperty prop = getProperty(LOOPS);
			return Integer.parseInt(prop.getStringValue());
		} catch (NumberFormatException e) {
			return 0;
		}
	}

	public String getLoopString() {
		return getPropertyAsString(LOOPS);
	}

	/**
	 * Determines whether the loop will return any samples if it is rerun.
	 * 
	 * @param forever
	 *            true if the loop must be reset after ending a run
	 */
	public void setContinueForever(boolean forever) {
		setContinueForever_private(forever);
	}

	private void setContinueForever_private(boolean forever) {
		setProperty(new BooleanProperty(CONTINUE_FOREVER, forever));
	}

	private boolean getContinueForever() {
		return getPropertyAsBoolean(CONTINUE_FOREVER);
	}

    /*
     * (non-Javadoc)
     * 
     * @see org.apache.jmeter.control.Controller#next()
     */
    public Sampler next() {
        if(endOfLoop()) {
            return null;
        }
        return super.next();
    }

	private boolean endOfLoop() {
		final int loops = getLoops();
		return (loops > -1) && (loopCount >= loops);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#nextIsNull()
	 */
	protected Sampler nextIsNull() throws NextIsNullException {
		reInitialize();
		if (endOfLoop()) {
			if (!getContinueForever()) {
				setDone(true);
			} else {
				resetLoopCount();
			}
			return null;
		}
		return next();
	}

	protected void incrementLoopCount() {
		loopCount++;
	}

	protected void resetLoopCount() {
		loopCount = 0;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#getIterCount()
	 */
	protected int getIterCount() {
		return loopCount + 1;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#reInitialize()
	 */
	protected void reInitialize() {
		setFirst(true);
		resetCurrent();
		incrementLoopCount();
		recoverRunningVersion();
	}
}